Provided on the lifting part is a support unit and/or a clamping unit for supporting or clamping in place a workpiece. The support unit, for example, may be a stay disposed for supporting a cylindrical workpiece. The clamping unit may comprise, for example, a tailstock or a similar clamping means in order to clamp in place a workpiece, in particular, in axial direction. Preferably, the lifting apparatus is disposed for use in grinding machines for grinding cylindrical workpieces.
For example, a lifting table is known from publication DE 36 709 U1. The lifting table comprises a table top, a base part and a lever arrangement with four levers that are hinged next to each other to form a closed circle. One of the joints of the lever arrangement is arranged on the table top, and the opposite joint is arranged on the base part. The other joints are free joints. At least one toggle lever mechanism is actuated via a drive in order to lift or lower the table top relative to the base part. A pushrod of the drive connects the toggle joint of the toggle lever mechanism with the free links of the lever arrangement.
In doing so, the drive is supported by the lever arrangement between the base part and the table top and moved along as the table top is being moved in lifting direction. This is not favorable, because the mass of the drive must also be completely moved along. Furthermore, it has been found that the start-up of the working position of such lifting tables is too inaccurate for many applications. In particular, when workpieces are supported or mounted in precision machines, the accurate adjustment of the working position of the lifting part of the lifting apparatus to a few micrometers must be possible.